/**
 * 设置cookie
 * @param {*} cname 键
 * @param {*} cvalue 值
 * @param {*} time 时间-天
 */
function setCookie(cname, cvalue, time) {
    var d = new Date();
    d.setTime(d.getTime() + (time * 24 * 60 * 60 * 1000));
    var expires = "expires=" + d.toUTCString();
    document.cookie = cname + "=" + cvalue + "; " + expires + ";path=/";
}

/**
 * 获取cookie
 * @param {*} cname 键
 * @returns 
 */
function getCookie(cname) {
    var name = cname + "=";
    var ca = document.cookie.split(';');
    for (var i = 0; i < ca.length; i++) {
        var c = ca[i];
        while (c.charAt(0) == ' ') c = c.substring(1);
        if (c.indexOf(name) != -1) return c.substring(name.length, c.length);
    }
    return "";
}

/**
 * 清除cookie
 * @param {*} name 键
 */
function clearCookie(name) {
    setCookie(name, "", -1);
}